Piezoelectric transducers have been commonly employed in various environments where energy conversion is required. These include electromechanical conversion systems such as measuring and testing equipment, electro-optical conversion systems such as optical modulators, etc. A practical application of piezoelectric transducers to electro-optical systems has involved the area of optical shutter controls such as are employed in laser modulators, Q-switches, etc. Typically, an electrical signal input is applied to a piezoelectric transducer through a coupling electrode bonded to the surface of the transducer, causing the transducer to launch a light beam-modifying acoustic wave into the medium upon which the transducer is mounted. In optical communication systems to which radio frequency (RF) signals may be coupled, the coupling of the RF signals to the transducer has been conventionally effected by way of a signal transmission wire soldered to the transducer electrode that is bonded to the surface of the transducer. Unfortunately, because of the extreme thinness of the transducer electrode and the manner in which a transducer electrode is formed on the surface of the transducer, cracks or separations are liable to occur in the electrode when the electrode is subjected to a high frequency (RF) input signal. A discussion of the bonding properties and characteristics of piezoelectric transducers may be found in an article by E. V. Sittig et al entitled "Bonded Piezoelectric Transducers for Frequencies Beyond 100 MHz", published in Ultrasonics, April 1969, pages 108-112, and in an article by A. H. Mietzler et al entitled "Characterization of Piezoelectric Transducers Used in Ultrasonic Devices Operating Above 0.1 GHz", published in the Journal of Physics Letters, Vol. 40, No. 11, October 1969, pages 4341-4352. Since the coupling of electrical energy between the signal transmission wire and the transducer electrode is conventionally effected by way of a solder joint over a relatively small area, destruction or deterioration of the bond between the electrode and the transducer is prone to occur because of severe localized heating created by the combination of the solder connection and the cracks or separations in the electrode which reduce the intended distribution of the electric field from the overall area of the electrode to a concentrated application of the electric field in that segment of the electrode to which the signal wire is soldered. In addition, a reduction in the electric field distribution area at the surface of the transducer electrode means that there is a corresponding reduction in the degree of application of the acoustic wave launched by the transducer into the acoustic-optic medium.
In an effort to reduce the undesirable heating effects at the transducer electrode, a heat sink may be coupled to the area of contact of the solder joint between the signal transmission wire and the transducer electrode. However, the coupling of the heat sink to the region of the transducer electrode at the signal transmission wire solder joint is such that some of the acoustic energy that is intended to be propagated from the transducer into the acoustic-optic medium is, instead, coupled into the heat sink and propagated away from the acoustic-optic medium.